Song th\u1ee7 l\u00f4 l\u00e0 c\u00e1ch ch\u01a1i \u0111\u01b0\u1ee3c nhi\u1ec1u anh em \u00e1p d\u1ee5ng b\u1edfi t\u1ef7 l\u1ec7 th\u1eafng t\u01b0\u01a1ng \u0111\u1ed1i cao. Thay v\u00ec 1 con nh\u01b0 b\u1ea1ch th\u1ee7, anh em s\u1ebd \u0111\u00e1nh 2 con s\u1ed1 kh\u00e1c nhau. Mu\u1ed1n ch\u01a1i song th\u1ee7 l\u00f4 hi\u1ec7u qu\u1ea3 th\u00ec c\u1ea7n ph\u1ea3i c\u00f3 ph\u01b0\u01a1ng ph\u00e1p soi c\u1ea7u chu\u1ea9n nh\u1ea5t.<\/p>\n